Poper Blocker

Block popups and popunders no matter where you click on a page.
When a popup or a popunder is blocked, a notification appears. You can view blocked content by clicking on its link in the notification, or click “Allow Always” to allow future popups from that site.
The whitelist can be managed via the extension's options page. If you're signed-in to Chrome, your settings will be synced across devices.